a) Field of the Invention:
This invention relates to fluid machines which have a rotor or a body with working chambers therein. The body or rotor has a concentric bore, called "rotor hub" and a control body closely fitting therein. The control body has a cylindrical outer face and control ports are provided in the control body and its outer face to control the flow of fluid into and out of the working chambers.
Such machines are for example, known from my U.S. Pat. Nos. 3,062,151; 3,136,260; 3,223,046; 3,273,342; 3,270,685; 3,277,834; 3,304,883; 3,416,460; 3,747,639; 3,757,648 or 3,468,262 or others.
b) Description of the Prior Art:
It is known from my elder patents, for example from my U.S. Pat. Nos. 3,062,151; 3,136,260; 3,223,046; 3,273,342; 3,270,685; 3,277,834; 3,304,883; 3,416,460; 3,747,639; 3,757,648 or 3,468,262 or others, to provide a rotor hub in the center of the rotor of a fluid machine which may have either a single or a plurality of working chamber groups in the rotor of the machine.
A control body is inserted into the rotor hub and has control ports for the control of flow of fluid into and out of the working chambers of the rotor.
In order to counter balance the fields of pressure which surround the control ports and which include the control ports I have already in my mentioned elder patents provided diametrically located fluid pressure pockets in the control body to build up and maintain therein and therearound counter acting fields of pressure which act in the opposed direction onto the control body and thereby make the control body float with little or almost no friction in the rotor bore or rotor-hub.
These machines have proven partially to be of high efficiency and greatest reliability and of very little friction at low and medial fluid pressure ranges. They work also satisfactorily temporarly at higher pressures.
However at the very high pressures in fluid which are presently sometimes desired, a little more friction would be acceptable if the leakage could thereby be reduced.
Recently, a number of patents have been granted to inventors, which have assigned their inventions to the Bosch corporation of Western Germany. Those patents are, for example:
U.S. Pat. Nos. 3,810,418 of Paul Bosch; 3,875,852 of Paul Bosch; 3,866,517 of Ulrich Aldinger, 3,893,376 of Gerhard Nonnenmacher
The latter mentioned patents have equivalent patent application publications (Deutsche Offenlegungsschriften) in Germany. These latter mentioned patents attempt to supply other or better solutions to my first mentioned elder own U.S. patents. However, the latter mentioned patents and applications deal with the same matter, as my previously mentioned elder U.S. patents, namely with the concentric floating of the control body in the rotor-hub. In all those cases, either the control body; floats in the rotor, or the rotor floats around the control body depending thereon, whether the rotor or the control body is flexibly mounted. At least all these mentioned patents and patent applications claim that the control body would float in a concentrical manner relative to the inner surface of the rotor-hub. As will be shown in the details of the invention, it is, however, not at all times assured, that the control body all times floats concentrically relative to the rotor-hub.
Some other patents in the field are U.S. Pat. Nos. 3,874,272; 3,874,274 or British patent 958,028.
My earlier patent application Ser. No. 910,809, now abandoned, defines unloading recesses on a control body or control pintle, which carries a rotor. The teaching and aim of the said application is, to force the rotor to float eccentrically relatively to the axis of the control pintle in order to bring the inner face of the rotor closer to the outer face of the control pintle in the high-pressure zone adjacent the high pressure control port.
The present invention now discovers, that similar means can be utilized to make the rotor float either centrically, eccentrically or float with a pre-determined limited eccentricity around the control pintle, when the unloading recesses are respectively located and when means to supply pressure fluid to actuate hydrodynamic pressure fields at partially eccentric or eccentric rotation of the rotor are added.
The invention thereby obtains reduced leakage or reduced friction and makes it possible to obtain any desired centric, eccentric or partial eccentric running of the rotor relative to the control-pintle.
The invention relates to fluid flow machines, wherein fluid flows through a control pintle into or out of working chambers in a rotor of such machine. The invention relates only to those of the above mentioned machines, which have substantially radially directed passage means to the respective chamber and wherein the cross-sectional area through the passage means is less than the cross-sectional area through the respective chamber, so, that a radial inwardly towards the control pintle directed force appears in the respective chamber of the rotor due to the fact, that a bottom is appearing in the chamber which is subjected to the pressure in the fluid in the chamber.
The machine may act as a compressor, pump, motor, engine or transmission.
My elder U.S. Pat. No. 3,223,046 of Dec. 14, 1965 shows a radial piston fluid flow machine, which has a control pintle which carries thereon a floating rotor. The cylinders are provided with passages towards the control pintle and the passages already have a smaller cross-section than the cylinders, whereby the mentioned bottom appears in the cylinders and provides a force onto the rotor, directed towards the control pintle.
The newer U.S. Pat. No. 3,866,517 of Mr. Aldinger of Bosch of Feb. 18, 1975 shows a similar machine as that of my elder U.S. Pat. No. 3,223,046 but with the addition of recesses which shall load themselves through the clearance between the rotor and the control body with a medial pressure. This patent provides the must of communication passages to send the pressure from the mentioned recesses to recesses on the diametric opposite portion of the control pintle. The Aldinger U.S. Pat. No. 3,866,517 fails to mention the known elder of my U.S. Pat. No. 3,223,046 as related former art.